Anyone ever try this battery pack out? I found it online, they're going for $30 plus shipping online which is quite a bit cheaper than the Fast Mac and Mophie Juice Packs. I wasn't able to fine much about it online. I found the battery case online here: iPhone 3G Battery Pack

For $30 I would be skeptical..........
I know the FASTMAC IV cost a bit more, but it boasts 3100ah!!
More than double all others i've seen.
Its a real battery, not like the little boosters everyone else is selling at the moment.

The only better option is to plug the power guzzling iPhone into the wall.
If your a "Power User" FastMac IV is the only way to go!!

I've tried the incase power slider and i really just dont like the idea of having to remove my case to use this. i also don't want my battery charging when it's already fully charged, so i got a recommendation at ilounge and bought this: Welcome to Just Mobile

and love it. there are two different models. the link posted above is the bigger/more powerful one. works well and charged more than just the iphone 3g. you can use it with anything that can be charged via a usb cord

works well and charged more than just the iphone 3g. you can use it with anything that can be charged via a usb cord

The FastMac IV also charges anything with a USB adapter. And it has independent power controls for charging phone (on/off) and for charging Aux. battery (on/off) thus you can leave it on the charger and turn it off if it doesnt need charge but would be redundant as the IV itself will turn off when fully charged.You can recharge 3 iPhones on one charge, while your phone is in the case. All ports are accessible, has cool little lights on the back for power-on and charge strength. And the super bright light for low light photos or finding your way around in the dark

Ive gone thru 3 car chargers?
and the cords arent long enough to use while talking.
You dont have to keep the phone in the charger, you just pop it in when you need to refill! If I know im going to be away from power for awhile (ie. convention, school, shopping, riding my motorcycle) I might slip in and carry pack, but if goin out on date, or in a meeting, just put it back in the glove box and know you got power waiting for you. I drive 2 hours eachway to work. I need a charge before i get there! and likewise coming home. I really dont like running less than 1/3 full, it always seems to go quick from there. This thing works real well for me. And its not as big as it looks, get used to it overnight.
Much better than one of those battery things hanging out the bottom...

i guess for everyone's different. i don't feel it's convenient for me to have to remove my iphone case to get it charged. i prefer having the battery charger hanging at the bottom vs being attached to my phone as a case